Various electronic devices, such as a television receiver, VCR, and air conditioner, have been demanded to have various functions, small, and thin, and reliably-operable remote controller is accordingly demanded for remotely controlling these devices.
A conventional movable contact assembly used in a conventional remote controller will be described. FIG. 3 is a sectional view of the conventional remote controller. Movable contact assembly 1 includes a base 1A having a sheet shape and made of elastic material, such as rubber, operation portions 1B projecting upward, and elastic portion 1C which has a dome shape and connects upper surface 1E of base 1A to lower surface 1D of operation portion 1B. Operation portion 1B has lower surface 1G having movable contact 2 thereon made of conductive material, such as carbon. Elastic portion 1C is thinner than base 1A. Lower surface 1F of base 1A of movable contact assembly 1 is placed on wiring board 3 having plural wiring patterns (not illustrated) on upper and lower surfaces of board 3. plural fixed contacts 4 facing movable contact 2 of movable contact assembly 1 by a predetermined gap are provided on upper surface 3A of wiring board 3. Electronic components, such as LED 5A and microprocessor 5B, are mounted on lower surface 3B of wiring board 3. Fixed contacts 4 are electrically connected to each other with movable contact 2 by an operation to movable contact assembly 1. The electronic components provide control circuit 5 for transmitting signals for remote control in response to the electrical connection. Case 6 having a substantial box-like shape and made of insulating resin has open holes 6A through which operation portions 1B of movable contact assembly 1 project upward movably, respectively. Case 6 accommodates movable contact assembly 1 and wiring board 3. The lower surface of wiring board 3 is covered with cover 7 made of insulating resin, thus providing a remote controller.
The remote controller having the above-mentioned structure is directed to an electronic device, such as a television receiver, a VCR, or an air conditioner. Predetermined operation portion 1B for power supply switching or volume control is depressed with, for example, a finger, and elastic portion 1C elastically deforms accordingly. Accordingly, operation portion 1B moves downward, and movable contact 2 contacts fixed contacts 4 on wiring board 3. Signals, such as infrared rays, for the remote control corresponding to this operation are transmitted from control circuit 5 to the electronic device, thereby remotely controlling the device to turn on/off the device and control a volume.
The finger is released off from operation portion 1B to remove an operation force causes elastic portion 1C to return to the original, domical shape by its elastic force. Operation portion 1B accordingly moves upward, and then, movable contact 2 is removed away from fixed contacts 4, hence allowing them to return to the status shown in FIG. 3.
In the conventional remote controller, elastic portion 1C elastically deforming upon being depressed is positioned between upper surface 1E of base 1A and operation portion 1B. This arrangement provides clearance 6B between lower surface 6A of case 6 and upper surface 1E of base 1A. Gap 6B is equal to the height of elastic portion 1C, hence making the remote controller thick.